Search

Turtle species in the Family Podocnemididae, including the Colombian endemic and critically endangered Magdalena River Turtle Podocnemis lewyana, characteristically present low recapture rates that preclude estimation of population parameters using maximum likelihood modeling. In our 12-year monitoring project with this species, we evaluated changes in relative abundances, proportions of sex/size classes, and individual body sizes and body conditions in a population in four channels in the middle Magdalena River drainage. We also inspected for associations between trends in changes in these variables and differences in hunting pressure and habitat degradation. To inspect for temporal and spatial demographic dynamics, we estimated variation in relative abundances using the Catch Per Unit Effort index, the total number of turtles captured over an entire 5-day sampling period using ten baited funnel traps. Relative abundances and the proportions of sex/size classes were different between sites and years. We found a significant decline in the proportion of females and juveniles over time, along with evidence that the females still present were smaller in body size. Our results support the hypothesis that hunting eliminates adult females from these sites, perhaps also translating into a reduction in recruitment. The lack of evidence of generalized declines in body condition of all size classes suggests that habitat degradation might contribute less to the population declines in this region. Our results also illustrate that even when recapture rates are low, monitoring turtles via standardized trapping may yield insights into the population's conservation status that other relative abundance indices cannot., (© 2024. The Author(s).)

States of India like Bihar, Uttar Pradesh, and West Bengal along the Ganga River, endure natural disasters periodically, resulting in repeated trends of economic loss and damages. Especially, most of the districts of Bihar, India, are prone to floods. Based on this background, this study aims to assess the flood vulnerabilities across districts of Bihar, India, employing data from the Central Water Commission from 1953 to 2020. Further, we explore trends and patterns of loss and damage due to flood risks in Bihar. Using the flood vulnerability integrated method and the principal component analysis, the index is constructed by incorporating the three major indicators: exposure, sensitivity, and adaptive capacity. This study is unique, and advances from previous studies in using a greater number of variables in exposure indicator. The proxy variable for each indicator is identified through both inductive and deductive approaches, and the composite index is constructed using all three indicators. Also, we identify the districts with high level of education and per capita income are less likely to expose flood vulnerability. The comparison of the districts reflects wide range of variation in terms of flood vulnerability as per their adaptive capacity and sensitivity. Specifically, these findings align with Target Sustainable Development Goal 11.5. This study addresses the policy for disaster prevention, risk reduction, and mitigation measures, as well as the enhancement of the capability of adaptation to floods by the affected community., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

To date, land use structure information has been employed extensively for ecological risk assessment (ERA) purpose in regional/landscape scales; in contrast, land use function (LUF) information-based ERA research is still scarce. Therefore, it is necessary to carry out more ERA case studies in macroscale with the help of pertinent LUF indicators. As an important way to construct production-living-ecology LUF indexes, this study employs the weighted stacking method and related economic statistical data for regional ecological risk assessment (RERA) purpose within Yellow River Delta High-efficiency Eco-economic Zone (YRDHEZ), China. This YRDHEZ-RERA research pointed out that (1) it was rational to use a series of economic statistical data to more comprehensively and precisely characterize regional production and living function grades in YRDHEZ. (2) The Yellow River Delta had lower agriculture and non-agriculture production functions, whereas the rest of the zone had higher production functions. (3) Most people lived in the south part, whereas north coastal zone had very low population density; the east part had higher per capita disposable income of urban/rural households than that of west. (4) The south part of the zone had higher production/living functions and integrated ecological risk source intensity than those of north coastal zone, whereas the coastal zone had higher ecology function, eco-environmental vulnerability, and final integrated ecological risk than those of inland region. As for regional ecological risk management, establishing nature reserve with strict spatial governance for coastal/estuarine wetlands and coordinating production/ecology functions of coastal salterns/breeding ponds are relevant feasible measures., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Potentially harmful element (PHE) bioavailability is important to environmental contamination and must be checked under several soil conditions. This study aimed to assess Fe, Mn, and PHE uptake by rice (Oryza sativa) grown on flooded and non-flooded Fe tailings collected from the Doce River basin after its collapse in Brazil. After 65 days of sowing, shoots and roots were harvested to determine PHE concentrations. The mean concentrations of Mn in shoots and Fe in the roots of rice grown on the flooded tailings were 2140 mg kg -1 and 15,219 mg kg -1 , respectively. Mn was extensively translocated from roots to shoots (translocation factor (TF) = 2). Conversely, Fe accumulated in roots (TF = 0.015) and caused morphological damage to this rice organ. The application of macro and micronutrients lessened Fe toxicity in the roots of rice cultivated on the flooded tailings. The flooding of tailings influenced more Fe accumulation than Mn accumulation by rice plants. The PHE Ag, As, Cd, Ni, Hg, Pb, and Sb exhibited low total concentrations (maximum of 9 mg kg -1 for Ni and a minimum of 0.2 mg kg -1 for Cd, Hg, and Sb), and it was not observed an increase in their availability under tailings flooding conditions., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Although intraspecific trait variation is increasingly recognized as affecting ecosystem processes, few studies have examined the ecological significance of among-population variation in behavioral traits in natural ecosystems. In freshwater habitats, crayfish are consumers that can influence ecosystem structure (e.g., macroinvertebrate communities) and function (e.g., leaf litter breakdown). To test whether crayfish behavioral traits (activity, boldness, and foraging voracity) are major contributors of leaf litter breakdown rates in the field, we collected rusty crayfish (Faxonius rusticus) from eight streams across the midwestern USA and measured behaviors using laboratory assays. At the same streams, we measured breakdown rates of leaf packs that were accessible or inaccessible to crayfish. Our results provide evidence that among-population variation in crayfish boldness and foraging voracity was a strong predictor of leaf litter breakdown rates, even after accounting for commonly appreciated environmental drivers (water temperature and human land use). Our results suggest that less bold rusty populations (i.e., emerged from shelter more slowly) had greater direct impacts on leaf litter breakdown than bold populations (P = 0.001, r 2  = 0.85), potentially because leaf packs can be both a shelter and food resource to crayfish. Additionally, we found that foraging voracity was negatively related to breakdown rates in leaf packs that were inaccessible to crayfish (P = 0.025, r 2  = 0.60), potentially due to a trophic cascade from crayfish preying on other invertebrates that consume leaf litter. Overall, our results add to the growing evidence that trait variation in animals may be important for understanding freshwater ecosystem functioning., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Tropical semiarid regions are naturally prone to environmental damage. Human activity can worsen this situation. To understand how human actions affect the ecosystem, plan land use effectively, and establish targeted management practices, assessing environmental vulnerability is crucial. This study focuses on a sub-basin receiving water transfers from the São Francisco River in Brazil's semiarid region. Here, we map and evaluate how land use and occupation alter natural vulnerability. We also propose zoning strategies to support water resource management and implement sustainable development policies in the region. To achieve this, we conducted an integrated analysis of physical factors (soil types, geology, climate, vegetation, and landforms) and spatial land-use data using geographic information systems (GIS) and map algebra techniques. Map algebra allowed us to combine these various datasets within the GIS environment, enabling the creation of maps that synthesize both natural and environmental vulnerability across the study area. Following analysis of these vulnerability maps, our findings reveal a high level of vulnerability. The areas with high to very high degrees of natural vulnerability coincide with the places that have high slopes, high altitudes, Lithic Neosols, and thick vegetation. Furthermore, the interaction between environmental factors and human activity exacerbates vulnerability. Based on the environmental vulnerability assessment, we defined four environmental management zones. These zones require distinct protection measures and management approaches. As a method to potentially improve the basin's vulnerability scenario, soil conservation measures are recommended. This approach is highly relevant for managing land in tropical semiarid regions and, with adaptations to specific regional factors, can be applied globally., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Rivers are vital and complex natural systems that provide a wide range of ecosystem services. This study presents a methodology for assessing the riverine provisioning and supporting ecosystem services, whose applicability has been demonstrated over the Budhabalanga River Basin of India. The Soil and Water Assessment Tool (SWAT) is used to generate streamflow time series at various ungauged sites, and then the streamflow is characterized for the evaluation of provisioning services. Further, the diversity and abundance of macroinvertebrates, along with the Lotic-invertebrate Index for Flow Evaluation (LIFE), is used to study the riverine supporting ecosystem services. The streams show intermittent behavior and strong seasonality for low flows, which limits the water availability, particularly during pre-monsoon season. The Baseflow Index (BFI) is greater than 0.6, indicating that groundwater contributes more than 60% of the total streamflow. Interestingly, despite the high BFI, the streams did not conform to the prevailing opinion that a greater baseflow contribution results in a later commencement of the low-flow period in the hydrological year. Furthermore, the study depicts significant variations in the diversity and abundance of the macroinvertebrates across the various sampling sites. However, the LIFE score across the sites remained consistent within a narrow range, i.e., 8 to 9, suggesting a steady supply of supporting ecosystem services. The results of the study can help the policymakers towards an informed decision making and the simplistic methodology proposed in this study can be replicated in other river basins for identifying vulnerable watersheds and prioritizing management actions., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

An increase in water temperature is one of the main factors that can potentially modify biogeochemical dynamics in lowland rivers, such as the removal and recycling of nitrogen (N). This effect of climate change on N processing deserves attention, as it may have unexpected impacts on eutrophication in the coastal zones. Intact sediment cores were collected seasonally at the closing section of the Po River, the largest Italian river and one of the main N inputs to the Mediterranean Sea. Benthic oxygen fluxes, denitrification, and dissimilatory nitrate reduction to ammonium (DNRA) rates were measured using laboratory dark incubations. Different temperature treatments were set up for each season based on historical data and future predictions. Higher water temperatures enhanced sediment oxygen demand and the extent of hypoxic conditions in the benthic compartment, favoring anaerobic metabolism. Indeed, warming water temperature stimulated nitrate (NO 3 - ) reduction processes, although NO 3 - and organic matter availability were found to be the main controlling factors shaping the rates between seasons. Denitrification was the main process responsible for NO 3 - removal, mainly supported by NO 3 - diffusion from the water column into the sediments, and much more important than N recycling via DNRA. The predicted increase in the water temperature of the Po River due to climate change may exert an unexpected negative feedback on eutrophication by strongly controlling denitrification and contributing to partial buffering of N export in the lagoons and coastal areas, especially in spring., (© 2024. The Author(s).)

Based on the panel data of 75 cities in the Yellow River Basin from 2000 to 2020, this manuscript measures the agricultural low-carbon production efficiency scientifically through the Super-SBM model. In addition, the deviation degree of agricultural industry is used as the index of structural adjustment. Finally, the spatial Durbin model is used to analyze the effect direction and degree of structural adjustment, financial support, and their synergistic effect on agricultural low-carbon production efficiency. The results show that ① the agricultural low-carbon production efficiency in the Yellow River Basin shows a trend of fluctuating downward and a spatial distribution pattern of "high in the east and low in the west". ② Structural adjustment in local region and adjacent areas has a significantly negative impact on agricultural low-carbon production, and the inhibitory effect in adjacent areas is more obvious, and the negative spatial spillover effect is strong. Financial support has a significantly positive impact on agricultural low-carbon production, but the spatial spillover effect of adjacent areas is not obvious. ③ By region, structural adjustment has a significantly negative impact on low-carbon agricultural production in the midstream and downstream regions, while financial support has a significantly positive impact on low-carbon agricultural production in the upstream region. The impact of control variables on agricultural low-carbon production varies from region to region. ④ The synergistic effect of structural adjustment and financial support in the whole and midstream region shows a significantly positive impact on agricultural low-carbon production, indicating that financial support has a certain correction effect on structural adjustment. The coefficient between the upstream and downstream regions is positive but not significant. The conclusions have important reference significance for promoting the ecological protection and high-quality development and agricultural low-carbon development in the Yellow River Basin., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Groundwater is the main source of water for agriculture, industry, and families in arid areas. At present, there is an urgent need to protect groundwater due to human activities. In this study, the Qingshui River Basin was selected as the study area. Based on the DRASTIC model, the DRASTIC-Land use type (DRASTICL) model and the analytic hierarchy process-DRASTICL (AHP-DRASTICL) model were constructed by optimizing the indicators and weights. And the three models were applied to calculate the groundwater vulnerability index (GVI), and the groundwater vulnerability map (GVM) was drawn. The validation results of Spearman correlation coefficient show that the DRASTICL model and the AHP-DRASTICL model have higher correlation, which indicates that the optimized model is more accurate. Among them, the AHP-DRASTICL model has the highest correlation coefficient (ρ = 0.92), which is more in line with the actual situation. The results of this study can provide scientific guidance for the protection and utilization of groundwater in the Qingshui River Basin. And it is of guiding significance for the study of groundwater vulnerability, especially for groundwater management in arid and semi-arid areas., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

An evaluation of flood vulnerability is needed to identify flood risk locations and determine mitigation methods. This research introduces an integrated method combining hydro-morphometric modeling and flood susceptibility mapping to assess Padma River Basin's flood risk. Flood zoning, flooding classes, and resource flood risk were explicitly analyzed in this river basin study. Flood risk was calculated using GIS-based hydro-morphometric modeling. Using Horton's and Strahler's methods, drainage density, stream density, and stream order of the Padma River Basin were determined. The Padma River Basin has five sub-basins: A, B, C, D, and E, with stream densities of 0.53 km -2 , 0.13 km -2 , 0.25 km -2 , 0.30 km -2 , and 0.28 km -2 and drainage densities of 0.63 km -1 , 0.16 km -1 , 0.29 km -1 , 0.35 km -1 , and 0.33 km -1 , respectively. Sub-basin A is the most prone to floods due to its high stream and drainage density, whereas B and C are the least susceptible. This study used elevation, TWI, slope, precipitation, NDVI, distance from road, drainage density, distance from river, LU/LC, and soil type to create a flood vulnerability map incorporating GIS and AHP with pair-wise comparison matrix (PCM). The study's flood zoning shows that the northeastern part of this basin is more likely to flood than the southwestern part due to its elevation and high-order streams. Moderate River Flooding, the region's most hazardous flood class, covers 48.19% of the flooding area, including 1078.30 km 2 of agricultural land, 94.86 km 2 of bare soil, 486.39 km 2 of settlements, 586.42 km 2 of vegetation cover, and 39.34 km 2 of water bodies. The developed hydro-morphometric model, the flood susceptibility map, and the analysis of this data may be utilized to offer long-term advance alarm insight into areas potentially to be invaded by a flood catastrophe, boosting hazard mitigation and planning., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

The guntea loach, Lepidocephalichthys guntea, is categorically common freshwater fish in Southeast Asia. Current study is the first elucidation on the reproductive feature of L. guntea including population structure, sex ratio (SR), size at first maturity (L m ), breeding period, and condition factor, emphasizing on the effect of environmental factors on reproduction of this fish in the Payra River (Southern Bangladesh) during July 2021 to June 2022. Using various conventional gears, 1128 individuals (534 males and 594 females) have been collected. Total length (TL), standard length (SL), and body weight (BW) of each fish were measured. Ovaries were cautiously dissected, removed, and precisely weighed. TL ranges from 4.6 to 9.7 cm (BW = 0.7-9.27 g) for male and 4.6-10.3 cm (BW = 0.8-10.75 g) for female. Both male (47.34%) and female (52.66%) populations were the leading group in 7.00-7.99 cm TL. Overall SR was not notably altered from anticipated value of 1:1 (male:female = 1:1.11). Nonetheless, monthly variations of SR specified females were considerably outnumbered males in each month excluding March-May. L m range was 6.4-7.0 cm, so larger than L m is recommended to exploit. Monthly changes in GSI indicated that the main spawning season was from March to June. The spawning season was substantially correlated with rainfall, nonetheless with temperature. Additionally, relative weight indicated that habitat was imbalanced with higher predators. A fishing ban is recommended during peak spawning to protect L. guntea in the Payra River and its surroundings based on current research., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

A crucial physiological indicator known as water use efficiency (WUE) (Foley et al.) assesses the trade-off between water loss and carbon uptake. The carbon and water coupling mechanisms, energy balance, and hydrological cycle processes in the ecosystem are impacted by climate change, vegetation dynamics, and land use change. In this study, we employed Sen trend analysis, the Mann-Kendall test, the land-use transfer matrix, and multiple linear regression analysis to investigate the regional and temporal dynamics of WUE and its reaction to climate change and land-use transfer changes in China. According to the findings, the annual average WUE in China was 0.998 gC/mm·m 2 from 2000 to 2017. Of the nine major river basins, the Continental Basin had the lowest WUE (0.529 gC/mm·m 2 ), and the Southwest River Basin had the highest WUE (0.691 gC/mm·m 2 ), while the Pearl River Basin and the Southeast River Basin had the highest WUEs (1.184 gC/mm·m 2 ). The Haihe River Basin and the Yellow River Basin were the key regions with elevated WUE. Forest had the greatest WUE (1.134 gC/mm·m 2 ; out of the nine major river basins), followed by shrub (1.109 gC/mm·m 2 ). Vegetation dynamics changes had a higher impact on WUE than climate change and land use changes, when the contributions of climate change, vegetation dynamics changes, and land use changes to WUE were separated. The largest climatic factor influencing variations in WUE was VPD (28.04% ± 3.98%), whereas among the vegetation dynamics factors, NDVI (33.75% ± 6.90%) and LAI (22.21% ± 2.11%) contributed the most. The transition from high to low vegetation cover led to a relative decrease in WUE, and vice versa, according to data on land use change in China from 2000 to 2017. Land use change made a positive impact to WUE change. The findings of this study may be helpful in China for choosing a suitable regional plant cover and managing local water resources sustainably., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Experiments are useful scientific tools for testing hypotheses by manipulating variables of interest while controlling for other factors that can bias or confuse the results and their interpretation. To ensures accuracy and reproducibility, experiments must have transparent and repeatable methodologies. Due to the importance of shredder invertebrates in organic matter processing, carbon cycling, and nutrient cycling, we tested experimentally the effect of different methodological approaches in microcosm experiments on the consumption and survival of shredders. We found that the shredder species, the presence or absence of the case, and the use or non-use of air-pumps in the microcosms did not affect shredder performance (i.e., consumption and survival). Furthermore, the type of water (stream or bottled) did not affect shredder performance. On the other hand, the amount of light had a negative effect on shredder performance, with constant light (i.e., 24 h) reducing shredder consumption and survival. Our results demonstrate that the use of different methodologies does not always result in changes in outcomes, thus ensuring comparability. However, luminosity is a critical factor that deserves attention when conducting microcosm experiments. Our findings provide valuable insights that can assist researchers in designing experiments with shredders from neotropical streams and conducting systematic reviews and meta-analyses., (© 2024. Sociedade Entomológica do Brasil.)

Diverse abiotic and biotic factors drive the ecological variation of communities across spatial and temporal dimensions. Within the Amazonian landscape, various freshwater environments exhibit distinct physicochemical characteristics. Thus, our study delved into the fluctuations of Odonata assemblages amidst distinct water bodies within Amazonia, encompassing two distinct climatic seasons. Comparative analysis was conducted on Odonata species diversity and assemblage composition across a blackwater pond, a lake, and a stream, spanning the initiation and culmination of the dry season in the southwestern Amazon region in Peru. Our methodology involved capturing adult Odonata using entomological nets on three separate occasions between 11:00 and 14:00 h for each water body in May (beginning of the dry season) and October (end of the dry season) of 2018. We also evaluated the influence of temperature, precipitation, and percent cloud cover on the abundance and richness of adult Odonata. Species richness and composition differed among the three water bodies in both periods of the dry season. No effect of the dry season periods on species richness and abundance was observed. However, except in the oxbow lake, the more abundant species were substituted to the end of the dry season. Our study highlights the influence of water body types on Odonata species diversity and composition. The effects of the sampling period during the dry season may not be immediately apparent in conventional diversity metrics, such as species richness and abundance. Instead, its effects manifest predominantly in the relative abundance of the species that compose these assemblages., (© 2024. Sociedade Entomológica do Brasil.)

On a global scale, flooding is the most devastating natural hazard with an increasingly negative impact on humans. It is necessary to accurately detect flood-prone areas. This research introduces and evaluates the Preference Ranking Organization METHod for Enrichment Evaluation (PROMETHEE) integrated with GIS in the field of flood susceptibility in comparison with two conventional multi-criteria decision analysis (MCDA) methods: analytical hierarchy process (AHP) and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). The Spercheios river basin in Greece, which is a highly susceptible area, was selected as a case study. The application of these approaches and the completion of the study requires the creation of a geospatial database consisting of eight flood conditioning factors (elevation, slope, NDVI, TWI, geology, LULC, distance to river network, rainfall) and a flood inventory of flood (564 sites) and non-flood locations for validation. The weighting of the factors is based on the AHP method. The output values were imported into GIS and interpolated to map the flood susceptibility zones. The models were evaluated by area under the curve (AUC) and the statistical metrics of accuracy, root mean squared error (RMSE), and frequency ratio (FR). The PROMETHEE model is proven to be the most efficient with AUC = 97.21%. Statistical metrics confirm the superiority of PROMETHEE with 87.54% accuracy and 0.12 RMSE. The output maps revealed that the regions most prone to flooding are arable land in lowland areas with low gradients and quaternary formations. Very high susceptible zone covers approximately 15.00-19.50% of the total area and have the greatest FR values. The susceptibility maps need to be considered in the preparation of a flood risk management plan and utilized as a tool to mitigate the adverse impacts of floods., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The spatial and temporal variations in the distribution, abundance, and assemblage structure of zooplankton were examined in the Chiffa Wadi River, north central Algeria. Samples were taken seasonally from autumn 2020 to summer 2022. Nine physical and chemical variables were recorded, and their relationship with the density of 39 zooplankton species was established using canonical correspondence analysis. In order to study the structure of the zooplankton, Shannon-Wiener diversity indices (H'), Margalef richness index (Dmg), Pielou evenness (E), and abundance were calculated. During the analysis, rotifera was the dominant group in the zooplankton community, represented by 27 taxa, followed by Cladocera (9 taxa) and Copepoda (3 taxa). The diversity index indicated the higher richness, abundance, and evenness of zooplankton at a eutrophic site (S2) compared with other sites. The canonical correspondence analysis (CCA) showed that the structure of zooplankton is influenced by local environmental factors. The present study demonstrates that anthropogenic activities including urban discharge and the construction of Algeria's Medea-Chiffa highway, which increased the nutrient load in the aquatic system, disrupted water quality. Consequently, the distribution and quantity of zooplankton were dramatically impacted by these changes in water quality., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Assessment of water availability in sub-humid regions is important due to distinct climatic and environmental conditions. In this study, Soil and Water Assessment Tool (SWAT) and Hydrologic Engineering Center-Hydrologic Modeling System (HEC-HMS) models have been assessed in simulating streamflows in the sub-humid tropical Kabini basin in Kerala, India, spanning 1260 km 2 . Calibration and validation utilized daily weather data from 1997 to 2015 from the Muthankera gauging station. The study investigated the impact of routing methods on runoff simulation in the ArcSWAT, exploring Muskingum and Variable Storage methods. Evaluation metrics encompassed Nash-Sutcliffe Efïciency (NSE), Coefficient of Determination (R 2 ), Percent bias (PBIAS), RMSE-observations standard deviation ratio (RSR), and Peak Percent Threshold Statistics (PPTS) approach for high-flow values. The result indicates that HEC-HMS outperforms SWAT concerning R 2 and NSE values during daily calibration and validation. Monthly simulations showed HEC-HMS closely aligning with SWAT (Variable storage), outperforming SWAT (Muskingum). The PPTS approach proved effective in simulating high-flow values. Both models exhibited proficiency in streamflow analysis within the study area, promising predictive potential for future hydrological studies in sub-humid regions., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The Gore Glen pond is located in the forested floodplain of the Gore River, in the Mid-Lothian region near Edinburgh, Scotland. This work has considered in detail the hydrology, hydrochemistry, and biodiversity of the pond together with all their interactions and in addition interactions with the adjacent Gore River. It is important as it is one of few studies considering all these issues for a pond located in a riverine floodplain. This work shows the pond is connected to the Gore River for discharge events in the river larger than a 1 in 5-year return period. For these events, the pond acts as an online storage feature and will attenuate the flow, thus contributing towards the mitigation of downstream flooding. These large events are also a potential source of the large amount of sediments, as well as adsorbed chemicals, accumulated in the pond. The open water surface of the pond is covered by duckweed, Lemna minor, for most of the year, and that has profound implications for the hydrobiological community and biogeochemical cycling. The system is characterised by nutrient release from sediments due to the extensive hypolimnion anoxia in the summer/autumn period caused by the decomposition of organic matter. Algae are mostly represented by epiphytic diatoms and the cyanobacterium Microcystis, but their development appears to be constrained by light penetration. The eutrophic conditions are also conducive for the population of Difflugia (Protozoa, Rhizopoda). This work improves our understanding of the ecological relations of testate amoebae-an important group which has recently been used as biological indicators for the analysis of paleoecological relationships and paleogeographical reconstructions., (© 2023. The Author(s).)

Land use changes have profoundly influenced global environmental dynamics. The Yellow River (YR), as the world's fifth-longest river, significantly contributes to regional social and economic growth due to its extensive drainage area, making it a key global player. To ensure ecological stability and coordinate land use demand, modeling the future land allocation patterns of the Yellow River Basin (YRB) will assist in striking a balance between land use functions and the optimization of its spatial design, particularly in water and sand management. In this research, we used a multi-objective genetic algorithm (MOGA) with the PLUS model to simulate several different futures for the YRB's land use between 1990 and 2020 and predict its spatial pattern in 2030. An analysis of the spatiotemporal evolution of land use changes in the YRB indicated that construction land expansion is the primary driver of landscape pattern and structure changes and ecological degradation, with climate change also contributing to the expansion of the watershed area. On the other hand, the multi-scenario simulation, constrained by specific targets, revealed that economic development was mainly reflected in land expansion for construction. At the same time, grassland and woodland were essential pillars to support the region's ecological health, and increasing the development of unused land emerged as a potential pathway towards sustainable development in the region. This study could be used as a template for the long-term growth of other large river basins by elucidating the impacts of human activities on land use and rationalizing land resource allocation under various policy constraints., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Low carbon sustainable development (LCSD) has become an inevitable choice, for which China has put forward a "dual-carbon" policy. The purpose of this study is to capture the interaction between the environment and the economy in the context of this goal, thus evaluating LCSD level from a systematic perspective. This paper proposes a super slack based measurement (SBM) model with a non-equal weight structure to assess the LCSD level. Firstly, a maximum influence minimum redundancy (MIMR) index selection algorithm is designed to establish input and output index systems, which avoids redundancy indexes. Secondly, the objective function of the original super SBM employs an equal weight structure, which leads results inadequately reflect the research preferences. Therefore, the weights of indexes are introduced to form an improved super SBM. Finally, 40 cities along the Yangtze River Economic Belt (YREB) are selected for empirical analysis. Results show that (1) the LCSD level of YRBE decreases from downstream to upstream to midstream; (2) Jiangsu, Zhejiang, and Sichuan provinces have higher LCSD levels, while Hunan and Jiangxi provinces have lower levels; and (3) up to 2021, there are 32 effective cities and 8 ineffective cities. The research implies that balancing the economy-environment relationship is crucial for higher efficiency. The LCSD evaluation method not only reflects the coordination level between the economy and the environment, but also integrates the research preference into the results, providing decision support for the government to formulate carbon reduction policies and allocate resources., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The Garua bacha, Clupisoma garua, holds considerable commercial and nutritional significance as a fish species. This study investigates the relationships between GSI (gonadosomatic index) and eco-climatic conditions, and provides comprehensive insights into several facets of reproduction, such as size at first sexual maturity (L m ), spawning season, peak spawning period, and proposes sustainable management strategies for C. garua in the Ganges River, northwestern, Bangladesh. Since January to December 2017, 570 female individuals have been gathered from the Ganges River using cast nets, gill nets, and square lift nets on a monthly basis. The total length (TL) of the specimens varied from 3.90 to 26.30 cm. L m was estimated as 14.30 cm based on the results of the TL vs. GSI, MGSI (modified gonadosomatic index), DI (Dobriyal index), 14.00 cm through TL-FL regressions, and 15.18 cm depending on L max for this species. Furthermore, the spawning period was observed from May to August, peaking in June and July, based on greater GSI, MGSI, and DI values. Throughout the peak spawning season, there was not a significant differ from a value of 100 in the relative weight (W R ) of the female species. During the spawning season, a substantial association between temperature and GSI (p = 0.0038); rainfall and GSI (p = 0.0043); DO and GSI (p = 0.0043); pH and GSI (p = 0.0002); and alkalinity and GSI (p = 0.0001) was detected. Analyzing a 55-year data series (1964-2018), it became clear that an increase in average air temperature of 0.0289 °C and a decrease in rainfall of 2.988 mm per year might possibly delay the spawning season of this species. As a consequence, the results of this study provide crucial information for developing management strategies to safeguard C. garua populations in the Ganges River and its adjacent ecosystems., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The water crisis may be solved by utilizing reclaimed water. Three reclaimed water sources have restored the lower sections of the Licun River, forming a landscaped river. In this paper, the river's water quality was monitored for a year, and the ecological concerns were analyzed using luminescent bacteria, chlorella, and zebrafish. The results indicated that although basic water quality indicators like COD and ammonia fluctuated along the river, the classification of water quality was primarily affected by factors such as flow rate and water depth. Under experimental conditions, the toxic inhibitory effect of river water on luminescent bacteria, chlorella, and zebrafish was related to the treatment process of reclaimed water. It was found that the reclaimed water produced by the MBR, along with the UV disinfection process, showed no detectable toxicity. In contrast, the MBBR process, when combined with coagulation, sedimentation, filtration, ozonation, and chlorination, seemed to be the source of this toxicity. Along the river, the results of water quality assessments and ecological risk assessments were different, indicating that both should be conducted to evaluate rivers replenished with reclaimed water., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Floods in Iran cause a lot of damage in different places every year. The 2019 floods of the Gorgan and Atrak rivers basins in the north of Iran were one of the most destructive events in this country. Therefore, investigating the flood hazard of these areas is very necessary to manage probable future floods. For this purpose, in the present study, the capability of Random Forest (RF) and Support Vector Machine (SVM) algorithms was investigated in combination with Sentinel series and Landsat-8 images to prepare the 2019 flood map. Then, the flood hazard map of these areas was prepared using the new hybrid Fuzzy Best Worse Model-Weighted Multi-Criteria Analysis (FBWM-WMCA) model. According to the results of the FBWM-WMCA model, 38.58%, 50.18%, 11.10%, and 0.14% of the Gorgan river basin and 45.11%, 49.96%, 4.17%, and 0.076% of the Atrak river basin are in high, medium, low, and no hazards, respectively. The highest flood hazard areas in Gorgan and Atrak rivers basins in the north, northwest, west, and east, and south and southwest are mostly at medium flood hazard. Also, the results of RF and SVM algorithms with an overall accuracy of more than 85% for Sentinel-1, Sentinel-2, and Landsat-8 images and 80% for Sentinel-3 images indicate that the flooding is related to the western, southwestern, and northern regions including agricultural, bare lands and built up. According to the obtained results and the efficiency of the FBWM-WMCA model, the Gorgan and Atrak rivers basins need proper planning for flood hazard management., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Thermal pollution creates substantial challenges that alter energy demand and produce reactive oxygen species that damage fish DNA, proteins, and lipids. Rhamdia voulezi is a species of fish native to the Iguaçu river, Paraná, Brazil, that does not have scientific records of minimum (CT min ) and maximum (CT max ) temperatures required for survival. As it is a top predator species in the food chain and lives at temperatures below 22 °C, the loss of the species can cause functional problems in controlling the ecosystem and energy flow. The study evaluated the tissue metabolism of the brain, heart, and muscle of R. voulezi (n = 72) subjected to acute thermal stress of 31 °C for 2, 6, 12, 24, and 96 h after acclimatization to 21 °C. The biochemical markers SOD, GPx, MDH, HK, and CK of the brain, PCO of the heart and CAT, glycogen, G6PDH, and ALT of muscle were significant. PCA, IBR, thermal sensitive, and condition factor suggested that R. voulezi has different physiological strategies for acclimatization to 31 °C to mobilize and sustain the metabolic needs of oxygenation and energy allocation/utilization for tissue ATP production., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The objective of the current research was to examine the water quality of the River Ravi and the River Sutlej, with a specific focus on potentially toxic elements (PTEs). Additionally, we sought to monitor the sources of pollution in these rivers by gathering samples from the primary drains that carry industrial and municipal waste into these water bodies. Furthermore, we aimed to evaluate the impact of PTEs in surface water on groundwater quality by collecting groundwater samples from nearby populated areas. A total of 30 samples were collected from these three sources: rivers (6 samples), drains (9 samples), and groundwater (15 samples). The analysis revealed that the levels of PTEs in the samples from these three resources having a mean value: arsenic (As) 23.5 µg/L, zinc (Zn) 2.35 mg/L, manganese (Mn) 0.51 mg/L, lead (Pb) 6.63 µg/L, and chromium (Cr) 10.9 µg/L, exceeded the recommended values set by the World Health Organization (WHO). Furthermore, PTEs including (As 84%), (Zn 65%), (Mn 69%), (Pb 53%), (Cr 53%), and (Ni 27%), samples were beyond the recommended values of WHO. The results of the Principal Component Analysis indicated that surface water and groundwater exhibited total variability of 83.87% and 85.97%, respectively. This indicates that the aquifers in the study area have been contaminated due to both natural geogenic factors and anthropogenic sources. These sources include the discharge of industrial effluents, wastewater from municipal sources, mining activities, agricultural practices, weathering of rocks, and interactions between rocks and water. Spatial distribution maps clearly illustrated the widespread mobilization of PTEs throughout the study area. Furthermore, a health risk assessment was conducted to evaluate the potential adverse health effects of PTEs through the ingestion of drinking groundwater by both children and adults. Health risk assessment result show the mean carcinogenic values for As, Cr, Pb and Ni in children are calculated to be (1.88E-04), (2.61E-04), (2.16E-02), and (5.74E-05), respectively. Similarly, the mean carcinogenic values for the above mentioned PTEs in adults were recorded to be (2.39E-05), (3.32E-05), (1.19E-03), and (7.29E-06) respectively. The total hazard index values for As, Zn, Cr, Pb, Mn, Cu, and Ni in children were observed to be (9.07E + 00), (9.95E-07), (4.59E-04), (5.75E-04), (4.72E-05), (2.78E-03), and (5.27E-05) respectively. The analysis revealed that As has an adverse effect on the population of the study area as compared to other PTEs investigated in this study., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

The present study reveals toxic metals, proximate composition, and growth conditions in seven fish species, aiding their nutritional importance and conditions. The samples of seven different small indigenous fish species, including Xenentodon cancila, Glossogobious giuris, Pseudambassis ranga, Puntius dorsolis, Mystus vittatus, Dawkinsia filamentosa, and Dawkinsia tambraparaniei, were collected in river Gadananathi, Tamilnadu, India. A total 14 fish samples were analyzed for lead, cadmium, and copper using atomic absorption spectrometry. The standard procedures were used to determine the length-weight and proximate composition of the seven fishes. The findings revealed that the seven fish species had variable amounts of metal buildup. Cu levels were highest in D. tambraparniei gills and lowest in M. vittatus gills and livers; nonetheless, substantial amounts of Cu were found in P. dorsalis livers. In the length-weight correlations of the regression parameters of coefficient value r 2 , the "a" and "b" values revealed a positive allometric growth rate in all fish species except G. giuris and M. vittatus. However, X. cancila had the highest composition in the proximate analysis, while D. tambraparniei and D. filamentosa had the highest protein content mean value at a significant level (P ≤ 0.05). Overall, discrepancies in nutritional content might be related to species, environmental circumstances, fish age and size, and food availability., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Impervious surface cover increases peak flows and degrades stream health, contributing to a variety of hydrologic, water quality, and ecological symptoms, collectively known as the urban stream syndrome. Strategies to combat the urban stream syndrome often employ engineering approaches to enhance stream-floodplain reconnection, dissipate erosive forces from urban runoff, and enhance contaminant retention, but it is not always clear how effective such practices are or how to monitor for their effectiveness. In this study, we explore applications of longitudinal stream synoptic (LSS) monitoring (an approach where multiple samples are collected along stream flowpaths across both space and time) to narrow this knowledge gap. Specifically, we investigate (1) whether LSS monitoring can be used to detect changes in water chemistry along longitudinal flowpaths in response to stream-floodplain reconnection and (2) what is the scale over which restoration efforts improve stream quality. We present results for four different classes of water quality constituents (carbon, nutrients, salt ions, and metals) across five watersheds with varying degrees of stream-floodplain reconnection. Our work suggests that LSS monitoring can be used to evaluate stream restoration strategies when implemented at meter to kilometer scales. As streams flow through restoration features, concentrations of nutrients, salts, and metals significantly decline (p < 0.05) or remain unchanged. This same pattern is not evident in unrestored streams, where salt ion concentrations (e.g., Na + , Ca 2+ , K + ) significantly increase with increasing impervious cover. When used in concert with statistical approaches like principal component analysis, we find that LSS monitoring reveals changes in entire chemical mixtures (e.g., salts, metals, and nutrients), not just individual water quality constituents. These chemical mixtures are locally responsive to restoration projects, but can be obscured at the watershed scale and overwhelmed during storm events., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Water, as an indispensable constituent of life, serves as the primary source of sustenance for all living things on Earth. The contamination of surface water with heavy metals poses a significant global health risk to humans, animals, and plants. Sharkiya Governorate, situated in the East Nile Delta region of Egypt, is particularly susceptible to surface water pollution due to various industrial, agricultural, and urban activities. The Bahr Mouse Stream, crucial for providing potable water and supporting irrigation activities in Sharkiya Governorate, caters to a population of approximately 7.7 million inhabitants. Unfortunately, this vital water source is exposed to many illegal encroachments that may cause pollution and deteriorate the water resource quality. In a comprehensive study conducted over two consecutive seasons (2019-2020), a total of 38 surface water samples were taken to assess the quantity of heavy metals in surface water destined for human consumption and other applications, supported by indices and statistics. The assessment utilized flame atomic absorption spectrophotometry to determine the concentration of key heavy metals including iron (Fe), manganese (Mn), cadmium (Cd), copper (Cu), lead (Pb), zinc (Zn), nickel (Ni), cobalt (Co), and chromium (Cr). The calculated mean value of the Water Quality Index (WQI) was found to be 39.1 during the winter season and 28.05 during the summer season. This value suggests that the surface water maintains good quality and is suitable for drinking purposes. Furthermore, the analysis indicated that the concentrations of heavy metals in the study area were below the recommended limits set by the World Health Organization and fell within the safe threshold prescribed by Egyptian legislation. Despite the identification of localized instances of illegal activities in certain areas, such as unauthorized discharges, the findings affirm that the Bahr Mouse stream is devoid of heavy metal pollution. This underscores the importance of continued vigilance and regulatory enforcement to preserve the integrity of these vital water resources., (© 2024. The Author(s).)

Monitoring and protecting freshwater habitats are paramount for a sustainable water management perspective. This study investigated potentially toxic elements (PTEs) in the potamic water of the Anday Stream Basin (Türkiye), Black Sea Region, for a hydrological year (from May 2020 to April 2021). Among PTEs, the highest average values were recorded for sodium (Na) at 41.3 mg/L and the lowest for mercury (Hg) at 0.009 μg/L and noted under quality guidelines. The stream was found to be at the level of "Low Heavy Metal Pollution" and "Low Contamination" based on the ecotoxicological risk indices. The highest calculated hazard quotient (HQ) value of 1.21E-02 for Cd was noted in the children via the dermal pathway and the lowest of 6.91E-06 for Fe in adults via the ingestion pathway. Results revealed a higher hazard index (HI) value of 1.50E-02 for Cd to children and the lowest of 1.98E-05 for Fe to adults. As a result of applying agricultural risk indices, the stream showed sodium adsorption ratio values less than 6 and was found to be "Excellent" for agriculture. However, the sodium percentage values were less than 20 and found "Permissible" and the magnesium hazard > 50 and noted as "Unsuitable" for agriculture. Statistical analysis revealed that natural factors mainly attributed to PTE contamination of the Anday Stream Basin., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

The amount of information available on the microplastic (MP) contamination in Goa's riverine water systems is currently limited. The abundance, size, colour, and polymer composition of microplastics in Chapora River surface water were investigated in this study. MPs in Chapora River surface water ranged from 0.1 particles/L (station 13) to 0.47 particles/L (station 5). The mean (± standard deviation) MP concentration was 0.25 (± 0.13) particles/L. Fibre was the dominant shape (77.15%), followed by fragments (12.36%), films (9.36%), and foam (1.12%). Most MPs were found in the 0.1-0.3 mm size range, then in the 0.3-1 mm and 1-5 mm. The dominant type of polymer studied was polyethylene terephthalate (PET; 46%), followed by high-density polyethylene (HDPE; 14%), polypropylene (PP; 5%), and polystyrene (PS; 1%). The risk assessment study indicated high risk with respect to PHI, while PLI shows low risk in the area. The source of MPs was mostly anthropogenic in nature in the region. When compared with other tropical rivers, MP pollution was relatively lower in the Chapora River. Nevertheless, the baseline data will help the local administration take mitigation measures to reduce the impact of MP pollution in the region., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Quantifying the drivers of water footprint evolution in the Yangtze River Delta is vital for the optimization of China's total water consumption. The article aims to decompose and predict the water footprint of the Yangtze River Delta and provide policy recommendations for optimizing water use in the Yangtze River Delta. The paper applies the LMDI method to decompose the water footprint of the Yangtze River Delta and its provinces into five major drivers: water footprint structure, water use intensity, R&D scale, R&D efficiency, and population size. Furthermore, this paper combines scenario analysis and Monte Carlo simulation methods to predict the potential evolution trends of water footprint under the basic, general, and enhanced water conservation scenario, respectively. The results show that (1) the expansion of R&D scale is the main factor promoting the growth of water footprint, the improvement of R&D efficiency, and the reduction of water intensity are the main factors inhibiting the increase of water footprint, and the water footprint structure and population size have less influence on water footprint. (2) The evolution trend of water footprint of each province under three scenarios is different. Compared to the basic scenario, the water footprint decreases more in Shanghai, Zhejiang, and Anhui under the general and enhanced water conservation scenario. The increase in water footprint in Jiangsu under the enhanced scenario is smaller than that of the general water conservation scenario., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Pentachlorophenol (PCP), a persistent organic pollutant, has been banned in many countries, but it is still used in China as a wood preservative, molluscicide, or reagent for fish-pond cleaning, which may pose risks to the ecosystem and humans. However, data on the occurrence of PCP in the environment are scarce in the recent decade. The Yangtze River was regarded as a priority area of PCP pollution according to previous documents. This study aimed to examine the spatial distribution of PCP in the Yangtze River water, the differences in dry and wet seasons, the ecological risk for aquatic organisms, and its removal efficiency in tap water treatment plants. The river water samples (n = 144) were collected from the upper, middle, and lower reaches across ten provinces (or municipalities) in December 2020 and June 2021, respectively. PCP was detected in 88.9% of all the samples, ranging from Max: 0.02) to aquatic organisms posed by PCP in the river. In addition, 100% removal of PCP in tap water treatment plants was observed, while the transformation products of PCP need further studies. The risk of human exposure to PCP through water ingestion only was negligible. However, human exposure risks of PCP in highly contaminated areas still require attention, considering its bioaccumulation and biomagnification in the environment., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This study aimed to optimize the methods for sampling and analyzing methylmercury (MeHg) concentrated within diffusive gradients in thin films (DGT) and its application to different water bodies. We explored the elution solution for MeHg, comprised of 1.13 mM thiourea and 0.1M HCl, optimizing its volume to 50 mL. In addition, we found that it is necessary to analyze the entire extraction solution after adjusting its pH, to ensure completion of the ethylation reaction. The DGT samplers were deployed in two distinct aquatic environments (i.e., Okjeong Lake and Nakdong River) for up to 6 weeks, and this study demonstrated to predict the time-weighted average concentration with a diffusion coefficient of 7.65 × 10 -6 cm 2 s -1 for MeHg in the diffusive gel. To assess the diffusive boundary layer (DBL) effects, the DGT samplers with different agarose diffusive gel thickness were deployed. The mass of MeHg accumulated in the DGT resin at a given time decreased with increasing diffusive gel thickness, because of creating longer diffusion pathways within thicker gels. The labile MeHg concentration estimated by the DGT in Okjeong Lake and Nakdong River are found in the range of 61-111 and 55-105 pg L -1 , respectively, which were found to be similar to the grab sampling data. Additionally, this study evaluated depth-dependent MeHg in Okjeong Lake. The vertical profile results showed that the concentration of MeHg at the depth of 2.3 and 15.7 m are about 1.5 and 4.6 times of the DGT installed at 0.3 m of the surface layer, respectively, suggesting potential mercury methylation in deep waters. These findings have practical implications for predicting bioavailability, assessing risks, and formulating strategies for water body management and contamination remediation., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

In the context of regional integration, it is more than crucial to compare and analyze the spatial correlation network structure and formation mechanism of high-quality economic development in the Yangtze River Economic Belt and the Yellow River Basin urban cities as an attempt to strengthen collaborative work on high-quality economic development in both river basins. The paper measured high-quality economic development of the Yangtze River Economic Belt and the Yellow River Basin from 2010 to 2021. Then, it employed social network analysis and the QAP method to study the network structure's characteristics and formation mechanism. The conclusion of the research illustrates a few points clearly that first, the high-quality economic development of the two rivers presents a complex and multithreaded network structure. Although the network structure is hold at a comparatively stable state, the correlation degree needs improvement. Second, cities such as Chongqing, Wuhan, Hefei, Nanjing, Hangzhou, Shanghai, and Changsha and cities like Zhengzhou, Xi'an, Luoyang, Yulin, Hulunbuir, Ordos, and Nanyang are at the very central as well as central position of the network. The spatial correlation networks of the Yangtze River Economic Belt and the Yellow River Basin can be divided into four plates: "agent plate," "main outflow plate," "bidirectional spillover plate," and "main inflow plate." Third, reverse geographical distance and differences in the digital economy attach great significance to the spatial correlation networks of the two basins. The difference in urbanization level makes significant impacts only on the spatial correlation network of the Yangtze River Economic Belt, while the difference in environmental regulation and material capital accumulation only significantly influences the spatial correlation network of the Yellow River Basin., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Biological communities have their biodiversity patterns affected by environmental, spatial, and biogeographic factors that vary from taxa to taxa, and often between life stages. This is especially true when there are differences in the habitat the species use in each of them. Individuals of the insect order Trichoptera are mostly aquatic in their larval stage and terrestrial in their adult stage, which may result in different behaviors and environmental requirements. Our goal was to evaluate the congruence between the larval and adult stages of Trichoptera in Amazonian streams regarding their abundance, richness, and assemblage composition. Additionally, we tried to identify the main environmental factors related to each life stage. For this, larvae and adults of Trichoptera were sampled in the same sites at 12 streams in the Caxiuanã National Forest, Pará state, Brazil. Adult assemblages had greater richness of genera and abundance of individuals than the larval ones, and there was no congruence in the genera composition between these life stages. Our results also showed that different environmental variables structured Trichoptera larvae and adults. Since the sampling of larvae and adults proved to be complementary in the studied streams, we advise that Trichoptera diversity surveys consider both life stages of these organisms., (© 2023. Sociedade Entomológica do Brasil.)

Achieving a harmonious alignment between the biological characteristics of fish and hydrodynamics patterns is crucial for ensuring the efficacy of fish passage facilities. In this study, based on the hydrodynamic characteristics of the river and the biological characteristics of fish, we evaluated the internal flow field in the nature-like fishway of Congen II hydropower station located along the Chabao river and explored methods to improve the operation efficiency. Based on comprehensive considerations of the flow field, turbulent kinetic energy, and the migration pathways of fish, it is found that the implementation of a continuous oblique bottom slope represents a more cost-effective and operationally convenient solution. The influence of different permutation of bulkheads in the nature-like fishway on operational efficiency was further examined. Our investigation revealed that the nature-like fishway with the continuous slope of 2% and the arrangement of three bulkheads in each row (model 3) exhibited a relatively simple velocity distribution and linear flow line, which poses challenges for fish in locating resting areas. In addition, the distribution of low turbulence kinetic energy area in the mainstream made it less favorable for fish to transition from the mainstream to the rest area within the fishway. The nature-like fishway with the continuous slope of 2% and the arrangement of two or three bulkheads in staggered rows (model 4) demonstrated better performance. Several potential fish migration routes for both model 3 and model 4 were proposed based on the numerical simulation results. In model 3, fish exhibited a continuous sprint through the concentrated high-speed area, which was less favorable for fish to rest and forage. In contrast, model 4 exhibited a diversified flow velocity distribution, enabling fish to make timely changes in their direction during migration. This feather proved to be advantageous in enhancing fish migration within the passage. The design of nature-like fishway in this study provides an important reference and technical support for the construction and optimization of the nature-like fishway for low dams, and is of great significance for restoring river connectivity destroyed by small hydropower construction and improving fish migration., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Rapid urbanization and industrialization promote economic growth as well as bring carbon emissions, which seriously threaten the eco-environment and socioeconomic sustainable development. Facing increasing resource constraints, improving carbon emissions efficiency (CEE) is conducive to promote coordinated development of economy and environmental protection. In recent years, regional economic integration (REI) has rapidly developed. It can not only promote factors flow between regions but also achieve industrial and economic agglomeration. However, few studies have been reported in the literature about the relationship between the REI and CEE. In this study, we first illustrate how the REI influences CEE in theory, then take the Yangtze River Delta (YRD) as a case study to conduct empirical research. The results show that (1) the overall CEE value in the YRD has exhibited an upward trend from 2000 to 2020, and its spatial distribution has revealed a significant auto-correlation pattern. (2) On the whole, the REI act a noteworthy positive impact on CEE. When considering types of cities, it is found to have significant positive impacts for the CEE in economically developed cities, while it exhibits a negative impact in the less-developed ones. (3) Upgrading industrial structure and increasing per capita GDP can promote the CEE, but hinder its growth in surrounding areas. Our findings suggest that the government should formulate a unified overall plan to facilitate REI development and establish a modern industrial system of clean and low-carbon to promote regional sustainable development., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

How to maintain the balanced stability and resilient development of rural systems is an important issue that needs urgent attention in the field of sustainable rural development at present. In this paper, the entropy method, spatial autocorrelation model, and Geodetector were used to explore the rural resilience level, spatial distribution characteristics, and driving factors of 31 cities in the urban agglomerations in the middle reaches of the Yangtze River (UAMRYR), and to put forward corresponding policy suggestions. The results are as follows: (1) From 2005 to 2020, rural resilience in the UAMRYR showed an upward trend with an average annual growth rate of 8.26%. The ranking of the three major urban agglomerations is Changsha-Zhuzhou-Xiangtan urban agglomerations > Wuhan urban agglomerations > Poyang Lake urban agglomerations. (2) During the study period, the spatial distribution of rural resilience gradually developed from a negative correlation to a strong positive correlation and generally showed the characteristics of high in the west and low in the east. (3) The urbanization rate, the size and structure of the economy, the difference in consumption and income between urban and rural areas, the local fiscal revenue, and the number of village committees are the key factors affecting the level of rural resilience. On this basis, we proposed policy recommendations to improve the economic, social, and ecological resilience of rural areas in the UAMRYR. The findings of this paper are expected to provide insights into the policy formulation of China's rural revitalization strategy., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The explosive growth of the logistics industry has led to an increase in energy consumption and carbon emissions. To reduce emissions and increase the efficiency of the logistics industry, we studied the driving factors and decoupling effects of carbon emissions of logistics industry (LICE). First, an energy coefficient method is used to calculate the LICE. Second, the Logarithmic Mean Divisia Index (LMDI) decomposition method is used to decompose the driving factors of LICE into five types. Third, the decoupling model is used to explore the decoupling relationship between economic growth and LICE. Considering Anhui Province as an example, this study describes the method's implementation process based on a comparison of the four Yangtze River Delta provinces and cities. The results indicate that the growth rate of LICE in Anhui Province has decreased during the research period, from 9.7% in 2013 to 2.1% in 2021; however, the Tapio decoupling elasticity has been approximately 0.4 for the last 2 years, remaining in a weak decoupling stage from economic development. The LMDI decomposition results indicate that the average contribution of economic level to carbon emissions is 1.763. This study proposes some solutions and recommendations for the logistics industry's low-carbon development to offer methodological and theoretical support for LICE research., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This study assessed the accumulation levels and ecological risks associated with seven heavy metals (As, Pb, Cd, Hg, Cu, Cr, Zn) in the surface sediments of the Bong Mieu River in Quang Nam Province, Vietnam. The sampling encompassed 10 locations (S1-S10), considering areas both impacted and less impacted by gold mining activities. The findings revealed elevated levels of heavy metal pollution and associated ecological risks attributable to gold mining. Heavy metal content varied within specific ranges: As (70.6-341.2 mg/kg), Pb (216.3-504.1 mg/kg), Hg (0.138-0.252 mg/kg), Cd (0.91-1.51mg/kg), Cu (18.3-45.5 mg/kg), Cr (10.5-19.1 mg/kg), and Zn (49.3-84.1 mg/kg). Among these elements, Hg, Cu, Cr, Zn, and Cd adhered to the acceptable limits of VNTR 43:2017/MONRE (VNTR 43:2017/MONRE: National Technical Regulation/Ministry of Natural Resources and Environment of Vietnam). However, As and Pb content at all locations exceeded these limits significantly, with As being 4.1-20 times higher and Pb 2.3-5.5 times higher. The pollution of Pb and As was attributed to waste discharge from gold mining activities, which carry substantial amounts of these metals in various forms. The I geo indicated heavy pollution of As and Pb in the sediments. Ecological risk factors were ranked as follows: E r i (As) > E r i (Pb) > E r i (Hg) > E r i (Cd) > E r i (Cu) > E r i (Cr) > E r i (Zn). The potential ecological risk (RI) due to combined heavy metal impact varied across locations, with S2 > S8 > S9 > S6 > S7 > S10 > S1 > S3 > S4 > S5, exhibiting low to moderate risk (RI values ranging from 73.4 to 252.8). The study area demonstrated high contamination levels for As and Pb, coupled with low to moderate potential ecological risks., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

The deterioration of superficial water quality is a significant concern in water management. Currently, most European rivers do not achieve qualitative standards defined by Directive 2000/60/EC (Water Framework Directive, WFD), while the health status of many surface water bodies remains unknown. Within this context, we propose a new methodology to perform a semi-quantitative analysis of the pressure state of a river, starting from easily accessible data related to anthropic activities. The proposed approach aims to address the endemic scarcity of monitoring records. This study proposes a procedure to (i) evaluate the relative pressure of different human activities, (ii) identify allocation points of different pollutant sources along the river using a raster-based approach, and (iii) determine a spatial biochemical water quality index. The developed index expresses the overall biochemical state of surface water induced by pollutant sources that may simultaneously impact a single river segment. This includes establishments under the so-called Seveso Directive, activities subjected to the IPPC-IED discipline, wastewater treatment plants, and contaminated sites. The methodology has been tested over three rivers in Northern Italy, each exposed to different industrial and anthropogenic pressures: Reno, Enza, and Parma. A comparison with monitored data yielded convincing results, proving the consistency of the proposed index in reproducing the spatial variability of the river water quality. While additional investigations are necessary, the developed methodology can serve as a valuable tool to support decision-making processes and predictive studies in areas lacking or having limited water quality monitoring data., (© 2024. The Author(s).)

The typology and classification of rivers are highly relevant concepts in the field of limnology and freshwater ecology. Water body typology systematically categorizes water bodies based on their natural attributes, while water body classification groups them based on specific criteria or purposes for management, regulatory, or administrative reasons. Both concepts play important roles in understanding and managing water resources effectively. This scientific article focuses on the ZAT River in Morocco as a model for studying low-flow and intermittent rivers. The objective is to develop an accurate model for the typology and classification of small, low-flow rivers into homogeneous classes based on natural and anthropogenic factors. The study also investigates the impact of human activities on altering the uniformity and reference nature of the water body. The typology of water bodies is carried out according to the European methodology specified in The European Commission's Water Framework Directive (WFD) in 2000. The classification of water bodies is conducted by assessing their chemical and biological quality using the weighted index (WI), the Iberian Biological Monitoring Working Group (IBMWP) index, and multivariate statistical methods such as principal component analysis (PCA) for confirming water quality assessment. The results indicate the possibility of dividing the basin into four water bodies. Water bodies show homogeneity in terms of chemical quality when human influence is minimal or during periods of high river flow. However, increased human influence and decreased river flows lead to heterogeneity in chemical quality, indicating an unstable state. This study is the first of its kind in arid and semi-arid intermittent rivers, where such an approach could be suggested to determine their typology and classification., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Carbapenem resistant Klebsiella pneumoniae causing severe infection resulting in morbidity and mortality have become a global health concern. K. pneumoniae with sequence type ST147 is an international high-risk clonal lineage, genomic studies have been done on K. pneumoniae ST147 isolated from clinical origin but genomic data for environmental K. pneumoniae ST147 is very scarce. Herein, K. pneumoniae IITR008, an extensively drug resistant and potentially hypervirulent bacterium, was isolated from Triveni Sangam, the confluence of three rivers where religious congregations are organized. Phenotypic, genomic and comparative genomic analysis of strain IITR008 was performed. Antibiotic susceptibility profiling revealed resistance to 9 different classes of antibiotics including ß-lactams, ß-lactam combination agents, carbapenem, aminoglycoside, macrolide, quinolones, cephams, phenicol, and folate pathway antagonists and was found to be susceptible to only tetracycline. The strain IITR008 possesses hypervirulence genes namely, iutA and iroN in addition to numerous virulence factors coding for adherence, regulation, iron uptake, secretion system and toxin. Both the IITR008 chromosome and plasmid pIITR008&#95;75 possess a plethora of clinically relevant antibiotic-resistant genes (ARGs) including bla CTX-M-15 , bla TEM-1 , and bla SHV - 11 , corroborating the phenotypic resistance. Comparative genomic analysis with other ST147 K. pneumoniae provided insights on the phylogenetic clustering of IITR008 with a clinical strain isolated from a patient in Czech with recent travel history in India and other clinical strains isolated from India and Pakistan. According to the 'One Health' perspective, surveillance of antibiotic resistance in the environment is crucial to impede its accelerated development in diverse ecological niches., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Microplastics are widely found in rivers and their sediments, which will cause harm to the water ecological environment. The Wei River is a first-class tributary of the Yellow River, the fifth largest river in the world, and has vulnerable ecological environment and most sediment in the world. However, understanding how anthropogenic activities and environmental factors affect the microplastics distribution in this river is not clear. Based on this, the spatiotemporal distribution of microplastics in the Wei River were investigated. The abundance of microplastics ranged from 1033 to 8333 items/m 3 and from 120 to 840 items/kg in the water and in the sediment, respectively. Fibers and fragments were the main shapes of Wei River, microplastics less than 500 μm were the main sizes, and black and white/transparent were the main colors. In Wei River, the abundance of microplastics in urban areas was higher than that in agricultural areas and mountainous areas. Furthermore, the correlation analysis revealed that microplastic abundance in the water was related to anthropogenic activities (population density, per capita GDP and distance) and environmental factors (water temperature, NH 3 -N, ORP), while in the sediments was correlated with anthropogenic activities (per capita GDP) and environmental factors (water temperature and NH 3 -N). This study reveals new patterns in microplastic pollution in the Wei River, underscoring the need for targeted environmental strategies. Our findings provide novel insights into the characteristics and distribution of microplastics, significantly adding to the current understanding of riverine microplastic pollution., (© 2024. The Author(s).)

Environmental flow (e-flow) is the water demand of one given ecosystem, which can become the flow regulation target for protection and restoration of river or estuarine ecosystems. In this study, an e-flow assessment based on the flow-ecological health index (EHI) relation model was conducted to improve ecosystem health of the Yangtze River Estuary (YRE). Monitoring data of hydrology, biology, and water environment in the last decades were used for the model establishment. For the description of the YRE ecosystem, an EHI system was developed by cumulative frequency distribution curves and adaption of national standards. After preprocessing original flow values into proportional flow values, the generalized additive model and Monte Carlo random sampling were used for the establishment of the flow-EHI relation model. From the model calculation, the e-flow assessment results were that, in proportional flow values, the suitable flow range was 1.05-1.35, and the optimum flow range was 1.15-1.25 (flows in Yangtze River Datong Station). For flow regulation in two crucial periods, flows of 42,630-65,545 m 3 /s or over 14,675 m 3 /s are needed for the suitable flow of YRE in summer (June-August) or January, respectively. An adaptive management framework of ecological health-based estuarine e-flow assessment for YRE was contrived due to the limitation of current established model when facing the extreme drought in summer, 2022. The methodology and framework in this study are expected to provide valuable management and data support for the sustainable development of estuarine ecosystems and to bring inspiration for further studies at even continental or global levels., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

The Doce River Basin (DRB) suffers with the adverse impacts of mining activities, due to its high level of urbanization and numerous industrial operations. In this study, we present novel insights into contaminant flow dynamics, seasonal variations, and the primary factors driving concentration levels within the region. We conducted an extensive analysis using a database sourced from the literature, which contained data on the contamination of arsenic (As) and lead (Pb) in the Doce River. Our primary aim was to investigate the patterns of As and Pb flow throughout the entire basin, their response to seasonal fluctuations, and the key parameters influencing their concentration levels. The results showed significant seasonal fluctuations in As and Pb fluxes, peaking during the rainy season. The 2015 Fundão dam breach in the DRB led to notable changes, elevating elemental concentrations, particularly As and Pb, which were subsequently transported to the Atlantic Ocean. These increased concentrations were primarily associated with iron and manganese oxides, hydroxides, and sulfates, rather than precipitation, as evidenced by regressions with low R 2 values for both As (R 2 = 0.07) and Pb (R 2 < 0.001), concerning precipitation. The PCA analysis further supports the connection between these elements and the oxides and hydroxides of Fe and Mn. The approach employed in this study has proven to be highly effective in comprehending biogeochemical phenomena by leveraging data from the literature and could be a model for optimizing resources by capitalizing on existing information to provide valuable insights for drainage basin management, particularly during crises., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

River nutrient enrichment is a significant issue, and researchers worldwide are concerned about phosphorus. The physicochemical characteristics and phosphorus (P) fractions of 36 sediment and water samples from the Ganga (Kanpur, Prayagraj, Varanasi) and Yamuna (Mathura, Agra, Prayagraj) rivers were examined. Among the physicochemical parameters, pH exceeded the permissible limit in Ganga and Yamuna River water and sediment samples. Electrical conductivity (EC) and alkalinity were within the permissible limits, whereas total nitrogen (TN) exceeded the limit in Yamuna water. The analysis of phosphorus fractions indicated the dominance of inorganic phosphorus (IP) (76% in Ganga and 96% in Yamuna) over organic phosphorus in both rivers, suggesting the mineralization and microbial degradation as major processes responsible for transforming OP to IP. The positive correlation of pH with IP, AP (apatite phosphorus), and NAIP (non-apatite inorganic phosphorus) explains the release of inorganic phosphorus under alkaline conditions. The correlation between total organic carbon (TOC), TN, and organic phosphorus (OP) indicated the organic load in the rivers from allochthonous and autochthonous sources. Phosphorus released from river sediments and the concentration of phosphate in overlying river water show a positive correlation, suggesting that river sediments may serve as phosphorus reservoirs. The average phosphorus pollution index (PPI) was above one in both rivers, with relatively higher PPI values observed in the Yamuna River, indicating the contamination of sediment with phosphorus, indicating the contamination of sediment with phosphorus. This study revealed variations in the P fractionation of the sediment in both rivers, primarily as a result of contributions from different P sources. This information will be useful for applying different mitigation techniques to lower the phosphorus load in both river systems., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)